Laser radio frequency switch based on vanadium dioxide and preparation method thereof

Abstract

The invention discloses a laser radio frequency switch based on vanadium dioxide and a preparation method thereof, and belongs to the technical field of microwaves. The radio frequency switch comprises a substrate, a phase change layer, a laser absorption layer, a radio frequency transmission layer and a laser unit which are sequentially arranged from bottom to top. Wherein the substrate is made of a sapphire material; the phase change layer is a high-quality vanadium dioxide film and is used for realizing on-off control of a radio frequency signal; the laser absorption layer is a titanium nitride film, has excellent 1550nm infrared laser absorption performance, and can quickly convert laser energy into heat and transfer the heat to the vanadium dioxide phase change layer below; the radio frequency transmission layer adopts a metal coplanar waveguide structure, is positioned above the laser heat absorption layer and is used for transmitting high-frequency signals; laser irradiation vertically acts on the top of the device, the phase change layer is accurately heated in a non-contact mode, rapid conversion of the phase change layer from an insulation state to a metal state is achieved, and therefore switching regulation and control of radio frequency signals are completed. Compared with a traditional electric pulse mode, the power divider has the advantages of being fast in response, low in power consumption, simple in structure, high in process compatibility and the like, and is suitable for high-frequency electronic systems of 5G communication, millimeter wave radar, terahertz modulation and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave switch devices, and in particular to a vanadium dioxide-based laser radio frequency switch. Background Art

[0002] RF switches are essential components in RF systems and are widely used in modern communications, radar, satellite communications, and for routing and power control of radio frequency (RF) signals. With the continuous advancement of information and communications technology and electronics, the demand for RF switches is increasing, particularly in high-frequency applications such as 5G communications, millimeter-wave communications, and radar systems. Traditional RF switches are primarily based on semiconductor technologies, such as PIN diodes and field-effect transistors, as well as microelectromechanical systems (MEMS). Compared to other traditional switch technologies, RF switches offer advantages such as higher operating frequencies, faster response speeds, low power consumption, long lifespans, and high integration. They are particularly well-suited for modern communications systems (such as 5G and millimeter-wave communications), radar systems, satellite communications, and other high-frequency applications. The emergence of new materials (such as phase-change materials and two-dimensional materials) has further improved the performance of RF switches, enabling them to meet more stringent technical requirements and driving the development of high-frequency communication systems towards higher speeds and lower power consumption. However, these technologies have limitations in terms of high-frequency performance, insertion loss, switching speed, and integration.

[0003] In recent years, RF switches based on phase-change materials have attracted widespread attention. Phase-change materials such as GeTe, GeSbTe, and vanadium dioxide exhibit significant resistance changes during the transition between their crystalline and amorphous states, giving them unique advantages in switching applications. For example, vanadium dioxide has low resistance in its crystalline state but significantly increases in its amorphous state. This significant resistance change can be used to flexibly and effectively switch RF signals.

[0004] Although phase change material RF switches have made some progress in the laboratory, they still face challenges in practical applications such as low heating efficiency, slow phase change speed and high energy consumption. These problems mainly stem from the poor heat conduction efficiency in the device structure, which makes it impossible for the phase change layer to reach the required temperature quickly and evenly. Summary of the Invention

[0005] To address the shortcomings of existing RF switches in heating efficiency, response speed, and power consumption, this paper proposes a method for preparing a vanadium dioxide-based laser RF switch. This RF switch utilizes 1550nm infrared laser irradiation. By introducing a laser absorption layer above the vanadium dioxide phase change layer, it achieves efficient absorption and thermal conversion of laser energy. This heat is then quickly transferred to the underlying phase change layer, triggering a phase change process and achieving high responsiveness to RF signals and low-power switching control. This structure helps improve thermal energy utilization efficiency, accelerates phase change rates, and overall enhances the transmission performance and integrated application potential of the RF switch.

[0006] The technical route for realizing the present invention is as follows:

[0007] A vanadium dioxide-based laser radio frequency switch, comprising: a substrate, a phase change layer, a laser absorption layer, a radio frequency transmission layer, and a laser unit; the substrate being the bottom layer, the phase change layer being located at the center of the substrate's upper surface, the phase change layer being smaller in planar dimensions than the substrate, a laser absorption layer being disposed on the upper surface of the phase change layer, the laser absorption layer being smaller in planar dimensions than the phase change layer; a radio frequency transmission layer being disposed in an edge region of the substrate's upper surface, the radio frequency transmission layer surrounding the phase change layer and the laser absorption layer, with the upper surface of the radio frequency transmission layer being higher than the upper surface of the laser absorption layer; and the upper surfaces of both the phase change layer and the laser absorption layer being partially covered with the radio frequency transmission layer.

[0008] The laser unit is located above the laser absorption layer, and the laser unit emits laser light, which is irradiated onto the laser unit and heats the laser unit.

[0009] Furthermore, the substrate material is sapphire, the laser absorption layer is titanium nitride, and the radio frequency transmission layer is gold.

[0010] Furthermore, the substrate size is: 10*10*0.5mm; the length and width of the laser absorption layer are: 20um*30um, and the thickness is 20-50nm; the length and width of the phase change layer are: 40um*60um, and the thickness is 50-150nm.

[0011] Furthermore, the laser unit uses an infrared laser with a wavelength of 1550 nm to irradiate the laser absorption layer.

[0012] A method for preparing a vanadium dioxide-based laser radio frequency switch, the method comprising the following steps:

[0013] Step 1: The substrate is cleaned with acetone, anhydrous ethanol, and deionized water in sequence to remove surface organic contaminants and particulate matter. The cleaned substrate is dried with nitrogen and placed in a plasma cleaner for further treatment to enhance surface cleanliness and optimize the adhesion of subsequent thin film deposition.

[0014] Step 2: Depositing a high-quality vanadium dioxide film with a thickness of 50-150 nm on the substrate treated in step 1 using a polymer-assisted deposition process;

[0015] Step 3: Photolithographically patterning the surface of the vanadium dioxide film obtained in step 2, then dry-etching the film using a reactive ion etcher, and then sequentially cleaning the film surface with acetone, anhydrous ethanol, and deionized water to remove the photoresist and processing residues, thereby obtaining a precisely patterned phase change layer;

[0016] Step 4: Photolithographically patterning the surface of the phase change layer obtained in step 3, and then sputtering a titanium nitride film with a thickness of 20-50 nm using a magnetron sputtering device. The film surface is then cleaned with acetone, anhydrous ethanol, and deionized water in sequence to remove the photoresist and processing residues, thereby obtaining a precisely patterned laser absorption layer.

[0017] Step 5: After the surface of the functional layer obtained in step 4 is photolithographically patterned, gold with a thickness of 200-300 nm is magnetron sputtered as a radio frequency transmission layer. The surface is then cleaned with acetone, anhydrous ethanol, and deionized water in sequence to remove the photoresist and processing residues to obtain a precisely patterned radio frequency transmission layer.

[0018] Step 6: Finally, the entire device is cleaned with acetone, anhydrous ethanol, and deionized water in sequence to clean the substrate surface and remove the photoresist residue, thereby completing the preparation of the vanadium dioxide-based laser radio frequency switch;

[0019] Step 7: Use a 1550nm infrared laser to heat the switching device obtained in step 6. The laser irradiates the surface of the phase change layer and heats it to the phase change temperature, triggering the phase change of the phase change layer. The RF signal is controlled through the synergistic effect of the laser and the RF transmission layer.

[0020] Furthermore, the specific process of the polymer-assisted deposition method in step 2 is as follows: dissolving polyethyleneimine in deionized water, stirring, then adding ethylenediaminetetraacetic acid, stirring until a uniform solution is formed, then adding ammonium metavanadate to the solution and continuing to stir until a transparent solution is formed, and finally transferring the solution to an Amicon ultrafiltration device. During ultrafiltration, magnetic stirring is performed under nitrogen pressure to filter out water in the solution; obtaining a precursor solution;

[0021] The precursor solution was then spin-coated on the substrate, and the spin-coating parameters were: first spinning at a speed of 1000 r / min for 10 s, and then spinning at a speed of 6000 r / min for 40 s.

[0022] Furthermore, the precursor liquid is spin-coated on the substrate, the spin-coated substrate is placed on a porcelain boat, and then sent into a tubular furnace with a set program for heat treatment. The entire process is carried out in an atmosphere of water vapor and nitrogen. After the program is completed and the temperature returns to room temperature, the porcelain boat can be taken out, and a high-quality vanadium dioxide film can be obtained on the substrate.

[0023] Furthermore, the substrate needs to be surface treated in advance before the photolithography in step 3. It is first cleaned with acetone, anhydrous ethanol, and deionized water for 5 minutes respectively, and then blown dry; the etching gas used by the reactive ion etcher is sulfur hexafluoride. After etching, it is cleaned with acetone, anhydrous ethanol, and deionized water respectively, and then blown dry.

[0024] Furthermore, in step 4, titanium nitride is used as the target material, and only Ar gas is introduced during sputtering; in step 5, when a gold target is used for magnetron sputtering, the interface layer must be sputtered first using a titanium target to achieve good adhesion of gold.

[0025] In summary, and in combination with the prior art, the beneficial effects of the present invention are:

[0026] By sequentially constructing a high-quality vanadium dioxide phase change layer, a laser absorption layer, and a metal RF transmission layer on a sapphire substrate, and introducing an infrared laser unit with a wavelength of 1550nm on top of the device, a compact, vertically stacked, and easy-to-integrate RF switch architecture is achieved. The laser absorption layer is a titanium nitride thin film, which is arranged on the phase change layer and has excellent infrared light absorption performance. It can efficiently absorb 1550nm laser and quickly convert it into heat, and effectively conduct it to the vanadium dioxide thin film phase change layer below, thereby greatly improving the thermal response speed and phase change efficiency under laser drive. The laser heating method has the advantages of non-contact, high response, and strong controllability. It can accurately trigger the insulating and metallic phase changes of vanadium dioxide within a nanosecond time scale, thereby realizing fast and stable RF signal switching control. Compared with the traditional electric pulse drive method, this structure significantly reduces energy consumption, avoids interference caused by heat diffusion, and improves the thermal efficiency and stability of the device. In addition, the coplanar waveguide structure RF transmission layer used has good impedance matching characteristics, which helps maintain signal integrity and ensures the transmission performance of the device in high-frequency environments. The overall structure is suitable for high-frequency electronic systems such as 5G communications, millimeter-wave radar, and terahertz imaging, and has excellent engineering feasibility and application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the technical route of the present invention.

[0028] Figure 2 Temperature variation over time in a tube furnace for annealing vanadium dioxide deposition.

[0029] Figure 3This is a schematic diagram of the equivalent operation of the switch in the "on state" and "off state" of the present invention.

[0030] Figure 4 This is a schematic diagram of the structure of the vanadium dioxide-based laser radio frequency switch of the present invention.

[0031] Figure 5 Schematic diagram of the laser heating principle of the present invention. DETAILED DESCRIPTION

[0032] In order to make the objectives, technical solutions and beneficial effects of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings.

[0033] A vanadium dioxide-based laser radio frequency switch, such as Figure 4 As shown, it includes a substrate, a phase change layer, a laser absorption functional layer, a radio frequency transmission layer and a laser irradiation unit arranged in sequence, wherein the phase change layer is arranged on the substrate, and the laser absorption functional layer partially covers the surface of the phase change layer, which is used to absorb laser energy and efficiently conduct heat to the phase change layer; the radio frequency transmission layer is arranged on the laser absorption layer and covers part of the phase change layer and the laser absorption layer to realize the controlled transmission of radio frequency signals; the laser irradiation unit is located on the top of the device, and vertically irradiates the laser absorption layer to achieve precise thermal triggering of the phase change, the substrate is sapphire material, which has excellent thermal conductivity and dielectric stability, which is beneficial to the thermal diffusion of the device and high-frequency signal control; the phase change layer is a high-quality vanadium dioxide film with a thickness of 50-150nm, which has the characteristics of reversible phase change from insulating state to metallic state, and is the core functional layer of radio frequency on-off control; the laser absorption functional layer is a titanium nitride film with a thickness of 20-50nm, which has a high absorption rate for 1550nm wavelength infrared laser, and can Light energy is converted into heat and rapidly conducted to the phase change layer, thereby improving the phase change response speed and thermal efficiency; the RF transmission layer is a coplanar waveguide structure made of gold material with a thickness of 200-300nm, which is used to achieve low-loss transmission of RF signals and form an effective conduction control interface with the phase change region. The laser irradiation unit emits an infrared laser with a wavelength of 1550nm, which is focused by the lens system and vertically incident on the titanium nitride laser absorption layer, and then activates the vanadium dioxide layer to undergo phase change through thermal conduction. When the laser is irradiated, the vanadium dioxide is converted into a low-resistance metallic state, and the RF signal is turned on; when the laser is turned off, the vanadium dioxide returns to a high-resistance insulating state, the RF signal is disconnected, and the switching function is completed. The structural design has clear levels and high vertical integration. The laser excitation method has the advantages of non-contact, fast response, and low power consumption, which significantly improves the thermal utilization efficiency and switching speed of the device. It is suitable for high-frequency microwave systems such as 5G communications, millimeter-wave devices, and terahertz regulation, and has good integrability and engineering application potential.

[0034] The phase change layer is located on the substrate and serves as the switching channel of the RF device. The length and width of the phase change layer are: 40um*60um, and the thickness is 50-150nm;

[0035] The laser absorption layer is located on the phase change layer and is used to enhance the absorption rate of 1550nm infrared laser and convert light energy into heat energy and conduct it to the phase change layer. In order to facilitate good heat conduction and not affect the RF transmission performance, this layer is partially stacked on the phase change layer. The length and width are: 20um*30um, and the thickness is 20-50nm;

[0036] The RF transmission layer is located above the laser absorption layer and is made of gold with excellent conductivity. Part of the gold covers the titanium nitride functional layer and the phase change layer to form good ohmic contact between the layers and form a coplanar waveguide structure to adapt to high-frequency environments. By designing appropriate width and gap, the RF transmission layer can achieve good impedance matching, reduce reflections and crosstalk, and ensure the integrity and stability of the RF signal in the device.

[0037] The laser unit is located at the top of the device and uses an infrared laser with a wavelength of 1550nm. Infrared lasers in the 1550nm band have a strong absorption rate for titanium nitride. Titanium nitride can absorb the laser light energy in a very short time and convert it into heat energy. Due to the good thermal conductivity of titanium nitride itself, it can be quickly transferred to vanadium dioxide, causing it to be heated to its critical temperature (about 68°C), undergoing a phase change and achieving a fast switching response. Compared with traditional electric heating methods, laser heating does not require the setting of complex electrodes or wires, avoiding electrical interference, simplifying the structural design, and introducing no additional parasitic capacitance / inductance.

[0038] The vanadium dioxide-based laser radio frequency switch proposed in the present invention sequentially constructs a phase change layer, a laser absorption layer, and a radio frequency transmission layer on a substrate, and introduces a 1550nm infrared laser unit above them to form a switch architecture with a simple structure, vertical stacking, and suitability for integration. The laser absorption layer is a titanium nitride thin film, which is arranged on the phase change layer and has excellent infrared absorption capability. It can significantly enhance the absorption efficiency of the 1550nm laser and efficiently convert the absorbed light energy into heat energy, which is quickly transmitted to the phase change layer below, thereby improving the thermal response rate and phase change driving efficiency of the device. By using a 1550nm infrared laser to achieve precise heating of the phase change layer, the thermal response speed and energy utilization efficiency are significantly improved, avoiding the heat diffusion and energy consumption problems existing in traditional electric heating methods. The structure is simple, highly integrated, and has the characteristics of fast response, low power consumption, and high isolation. It is suitable for new generation high-frequency electronic systems such as 5G communications, millimeter-wave radar, and terahertz sensing.

[0039] like Figure 1As shown, it is a schematic diagram of the technical route of the present invention, showing the entire process from vanadium dioxide thin film deposition, patterned etching, laser absorption layer, construction of radio frequency transmission layer and even laser heating integration, and clearly expressing the logical process and key steps of device preparation.

[0040] like Figure 3 Figure 2 shows the equivalent operation of the RF switch described in the present invention in the "on" and "off" states. When laser light is turned on and irradiates the laser absorption layer, the absorbed light energy is rapidly converted into heat, which is then transferred to the underlying phase change layer, raising its temperature to approximately 68°C. The material then transforms into a low-resistance metallic phase, allowing the RF signal to pass through, turning the switch on and appearing in the "on" state. When the laser light is turned off, the vanadium dioxide remains in its high-resistance insulating phase, blocking the RF signal and placing the switch in the "off" state. This structure implements high-frequency microwave switching functionality with electrodeless triggering and rapid thermal response.

[0041] like Figure 4 The figure shows the structure of the vanadium dioxide-based laser radio frequency switch of the present invention. Its substrate is sapphire with a thickness of 500μm, and the thickness of the vanadium dioxide film is 50-150nm. It is achieved by polymer-assisted deposition combined with tubular furnace annealing. The laser absorption functional layer is arranged on the vanadium dioxide phase change layer. It is a titanium nitride film with a thickness of 20-50nm. It has excellent infrared absorption performance and can efficiently absorb 1550nm infrared laser and convert it into heat, which is then transmitted to the vanadium dioxide film below to trigger the phase change. The radio frequency transmission layer is a coplanar waveguide structure composed of sputtered metal gold with a thickness of 200-300nm. A window is reserved at the top for laser irradiation. The overall structure is stacked vertically for easy process compatibility and integration.

[0042] like Figure 5 Figure 2 shows a schematic diagram of the laser heating principle of the present invention. An infrared laser beam is collimated and focused by a lens system, then irradiated perpendicularly onto the surface of the vanadium dioxide film. The laser creates thermal excitation in a localized area of ​​the film, rapidly causing the vanadium dioxide to reach its phase transition temperature. Due to the laser's spatial focusing and temporal controllability, it effectively improves thermal efficiency and avoids increased power consumption and structural damage caused by widespread heat diffusion.

[0043] The preparation method of the present invention is as follows:

[0044] Step 1: Clean the substrate with acetone, anhydrous ethanol, and deionized water for 30 minutes each, then blow dry the substrate surface with a nitrogen gun, and use a plasma cleaner to further remove residual impurities on the surface;

[0045] Step 2: Prepare a vanadium dioxide precursor solution by dissolving 4 g of polyethyleneimine in 120 ml of deionized water. After stirring for 15 minutes, add 4 g of ethylenediaminetetraacetic acid and stir until a homogeneous solution is formed. Then, add 1.6 g of ammonium metavanadate and continue stirring until a transparent solution is formed. Finally, transfer the solution to an Amicon ultrafiltration device. During ultrafiltration, magnetic stirring is required under a nitrogen pressure of 0.3 MPa to filter out water in the solution.

[0046] The precursor film was spin-coated on the substrate surface using a spin coater. The spin coating parameters were set as follows: 1000 r / min for 10 seconds, then 6000 r / min for 40 seconds. The film was then annealed in stages using a tube furnace. The tube furnace parameters were as follows: Figure 2 As shown, a vanadium dioxide film with a thickness of 50–100 nm was prepared using polymer-assisted deposition;

[0047] Step 3: Use photolithography and reactive ion etching to achieve vanadium dioxide patterning. First, pretreat the substrate on which the thin film has been deposited: clean the sample surface with acetone, anhydrous ethanol, and deionized water for 5 minutes respectively, and then blow dry with a nitrogen gun. Heat at 120 degrees Celsius for 5 minutes, spin-coat the sample surface with a photoresist model of AZ6112. The spin-coating program parameters are set to: 1000r / min spin coating for 10s, then 3000r / min spin coating for 30s, then heat at 100 degrees Celsius for 60s, then align the pattern mark of the mask for UV exposure for 4s, then soak in developer and deionized water for 40-50s respectively, blow dry the surface, and then perform dry etching to obtain a precisely patterned vanadium dioxide phase change layer.

[0048] Step 4, the same pretreatment operation as step 3, followed by heating at 120 degrees Celsius for 5 minutes, spin coating the sample surface with a photoresist model AZ5214, and the spin coating program parameters are set as follows: 1000 r / min spin coating for 10 seconds, then 3000 r / min spin coating for 30 seconds, followed by heating at 100 degrees Celsius for 60 seconds, and then UV exposure for 3 seconds aligned with the pattern mark of the mask, and then heating on a hot plate at 120 degrees Celsius for 90 seconds and flood exposure for 30 seconds, followed by soaking in developer and deionized water for 40-50 seconds respectively. After drying the surface, magnetron sputtering titanium nitride forms a laser absorption layer;

[0049] Step 4: The same pretreatment operation as step 3 is followed by heating at 120 degrees Celsius for 5 minutes, and spin coating of AZ5214 photoresist is performed on the sample surface. The spin coating program parameters are set as follows: 1000 r / min spin coating for 10 seconds, then 3000 r / min spin coating for 30 seconds, followed by heating at 100 degrees Celsius for 60 seconds, and then UV exposure for 3 seconds aligned with the pattern mark of the mask, and then heating on a hot plate at 120 degrees Celsius for 90 seconds and flood exposure for 30 seconds. Then, the sample is immersed in developer and deionized water for 40-50 seconds respectively. After drying the surface, a metal layer is magnetron sputtered to form a radio frequency transmission structure. The graphic design adopts a coplanar waveguide structure.

[0050] Step 5: Clean the residual glue on the surface of the device and complete the overall packaging;

[0051] Step 6: Integrate a 1550nm infrared laser above the device surface. The laser output power ranges from 0 to 1100mW. The laser beam is focused and precisely irradiated onto the laser absorption functional layer through an optical lens system. The laser absorption functional layer is a titanium nitride thin film with excellent infrared absorption ability. It can efficiently convert laser energy into heat and conduct it to the vanadium dioxide phase change layer below, thereby driving it to undergo a phase transition from an insulating state to a metallic state, realizing the RF signal switching function of non-contact laser heating control.

[0052] The laser-driven vanadium dioxide phase-change RF switch proposed in this invention incorporates a laser absorption layer to enhance the heat absorption efficiency of 1550nm infrared lasers, improving the thermal excitation response of the phase-change layer and achieving efficient thermal management and optimized energy utilization. The device boasts a simple structure, fast response, strong integration, and low power consumption. It is suitable for applications such as high-frequency communications, millimeter-wave systems, and terahertz modulation, and possesses significant scientific research value and potential for industrialization.

Claims

1. A vanadium dioxide-based laser radio frequency switch, comprising: A substrate, a phase change layer, a laser absorption layer, a radio frequency transmission layer, and a laser unit; the substrate is located at the bottom layer, the phase change layer is located at the center of the upper surface of the substrate, the planar size of the phase change layer is smaller than the substrate, a laser absorption layer is provided on the upper surface of the phase change layer, and the planar size of the laser absorption layer is smaller than the phase change layer; a radio frequency transmission layer is provided in the edge area of ​​the upper surface of the substrate, the radio frequency transmission layer surrounds the phase change layer and the laser absorption layer, and the upper surface of the radio frequency transmission layer is higher than the upper surface of the laser absorption layer; the upper surfaces of the phase change layer and the laser absorption layer are partially covered with the radio frequency transmission layer; The laser unit is located above the laser absorption layer, and the laser unit emits laser light, which is irradiated onto the laser unit and heats the laser unit.

2. The vanadium dioxide-based laser radio frequency switch according to claim 1, characterized in that: The substrate material is sapphire, the laser absorption layer is titanium nitride, and the radio frequency transmission layer is gold.

3. The vanadium dioxide-based laser radio frequency switch according to claim 1, characterized in that: The substrate size is: 10*10*0.5mm; the length and width of the laser absorption layer are: 20um*30um, and the thickness is 20-50nm; the length and width of the phase change layer are: 40um*60um, and the thickness is 50-150nm.

4. The vanadium dioxide-based laser radio frequency switch according to claim 1, characterized in that: The laser unit irradiates the laser absorption layer with infrared laser having a wavelength of 1550 nm.

5. A method for preparing a vanadium dioxide-based laser radio frequency switch, the method comprising the following steps: Step 1: The substrate is cleaned with acetone, anhydrous ethanol, and deionized water in sequence to remove surface organic contaminants and particulate matter. The cleaned substrate is dried with nitrogen and placed in a plasma cleaner for further treatment to enhance surface cleanliness and optimize the adhesion of subsequent thin film deposition. Step 2: Depositing a high-quality vanadium dioxide film with a thickness of 50-150 nm on the substrate treated in step 1 using a polymer-assisted deposition process; Step 3: Photolithographically patterning the surface of the vanadium dioxide film obtained in step 2, then dry-etching the film using a reactive ion etcher, and then sequentially cleaning the film surface with acetone, anhydrous ethanol, and deionized water to remove the photoresist and processing residues, thereby obtaining a precisely patterned phase change layer; Step 4: Photolithographically patterning the surface of the phase change layer obtained in step 3, and then sputtering a titanium nitride film with a thickness of 20-50 nm using a magnetron sputtering device. The film surface is then cleaned with acetone, anhydrous ethanol, and deionized water in sequence to remove the photoresist and processing residues, thereby obtaining a precisely patterned laser absorption layer. Step 5: After the surface of the functional layer obtained in step 4 is photolithographically patterned, gold with a thickness of 200-300 nm is magnetron sputtered as a radio frequency transmission layer. The surface is then cleaned with acetone, anhydrous ethanol, and deionized water in sequence to remove the photoresist and processing residues to obtain a precisely patterned radio frequency transmission layer. Step 6: Finally, the entire device is cleaned with acetone, anhydrous ethanol, and deionized water in sequence to clean the substrate surface and remove the photoresist residue, thereby completing the preparation of the vanadium dioxide-based laser radio frequency switch; Step 7: Use a 1550nm infrared laser to heat the switching device obtained in step 6. The laser irradiates the surface of the phase change layer and heats it to the phase change temperature, triggering the phase change of the phase change layer. The RF signal is controlled through the synergistic effect of the laser and the RF transmission layer.

6. The method for preparing a vanadium dioxide-based laser radio frequency switch according to claim 5, wherein: The specific process of the polymer-assisted deposition method in step 2 is as follows: dissolving polyethyleneimine in deionized water, stirring, then adding ethylenediaminetetraacetic acid, stirring until a uniform solution is formed, then adding ammonium metavanadate to the solution and continuing to stir until a transparent solution is formed, and finally transferring the solution to an Amicon ultrafiltration device. During ultrafiltration, magnetic stirring is performed under nitrogen pressure to filter out water in the solution; obtaining a precursor solution; The precursor solution was then spin-coated on the substrate, and the spin-coating parameters were: first spinning at a speed of 1000 r / min for 10 s, and then spinning at a speed of 6000 r / min for 40 s.

7. The method for preparing a vanadium dioxide-based laser radio frequency switch according to claim 5, wherein: The precursor liquid is spin-coated on the substrate, the spin-coated substrate is placed on a porcelain boat, and then sent into a tubular furnace with a set program for heat treatment. The entire process is carried out in an atmosphere of water vapor and nitrogen. After the program is completed and the temperature returns to room temperature, the porcelain boat can be taken out, and a high-quality vanadium dioxide film can be obtained on the substrate.

8. The method for preparing a vanadium dioxide-based laser radio frequency switch according to claim 5, wherein: Before the photolithography in step 3, the substrate needs to be surface treated in advance. First, it is cleaned with acetone, anhydrous ethanol, and deionized water for 5 minutes respectively, and then blown dry. The etching gas used by the reactive ion etcher is sulfur hexafluoride. After etching, it is cleaned with acetone, anhydrous ethanol, and deionized water respectively, and then blown dry.

9. The method for preparing a vanadium dioxide-based laser radio frequency switch according to claim 5, wherein: In step 4, titanium nitride is used as the target material, and only Ar gas is introduced during sputtering. In step 5, when a gold target is used for magnetron sputtering, a titanium target must be used to sputter the interface layer first to achieve good adhesion of gold.

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